1. Field of the Invention
The present invention relates to an ultra violet rays generator (UV generator) by means of microwaves exitation comprising a step of irradiating microwaves to an ultra violet rays lamp (UV lamp), such as an electrodeless lamp etc. in a microwave cavity, and more particularly, to a UV generator detachable of an ultra violet rays reflector (UV reflector) from focus ray type to parallel rays type etc., without changing the capacity of a microwave cavity (impedance), and thus, becoming changeable of rays, for example, from focus rays to parallel rays or contrary to this without changing microwave efficiency, and furthermore possible of obtaining UV of low temperature excluding infra red rays (IR), and thus, becoming possible of the irradiation in high efficiency to the substrates which are damaged by high temperature heat, such as plastics.
2. Description of the Prior Art
There are conventionally known UV generators, such as a UV generator shown in FIG. 3.
In FIG. 3, an upper part of the generator is omitted, which includes a microwave generator and a wave guide, because of the same as FIG. 1, and thus, the omitted part will be explanated with FIG. 1.
The UV generator shown in FIG. 3 consists of a microwave generator 1, a wave guide 2, both of them being shown in FIG. 1, a microwave cavity 3, and a UV lamp 4, both of them being shown in FIG. 3. In said generator, the microwaves 6 which are generated from a microwave antenna 5 of the microwave generator 1 are introduced into the microwave cavity 3 through a slot 8 bored in an upper wall 7 of the microwave cavity 3. At this time, the UV lamp 4 is irradiated and exited with the microwaves 6 to generate ulta violet (UV) 9. The obtained UV are reflected by a curved reflecting membrance 10 formed on the inner wall 3a of the microwave cavity 3, and then, are supplied to irradiate the substrate which are not shown in the drawings, through a mesh 11.
In said generator shown in FIG. 3, however, the direction of the reflected UV is usually invariable and the variation or change thereof is impossible since the reflecting membrance 10 is integrally formed with the wall of the microwave cavity 3. If the direction wants to be changed, the wall of microwave cavity 3 must be changed. This change of the wall will result in the change of the capacity (volume) of the microwave cavity 3, and as a result, the impedance of the microwaves and microwaves effeciency will be changed and thus, the UV having constant strength can not be obtained.
Furthermore, according to the generator shown in FIG. 3, the IR produced together with the UV and contained in the UV can not be excluded from the UV, and thus, the obtained UV are accompanied with heat, and accordingly, it is impossible to irradiate the UV to the substrates which hate high temperature heat.